Running is a popular activity. However, participation in running declines steadily with age. Reasons for this age related decline in running participation include weight gain, decreasing fitness levels and injury. For instance, when jogging or running a person's joints, such as the ankle and knee joints, become stressed due to the impacting of the feet with a surface on which the person is jogging or running. Over time, these impacts on the person's joints may be substantial and as such, the person may find running uncomfortable or even be unable to run due to the discomfort experienced. Therefore, it is desirable to have an exercise, training and recreational device that simulates the activity of running while alleviating the impact injuries associated with it. In particular, it is desirable for such a device to recruit and train the same muscles used in running so people can continue to train and participate in running activities regardless of their age, weight and fitness level, without the risk of sustaining injuries.
In an attempt to reduce the stresses on joints elliptical trainers have been developed. In general terms, elliptical trainers are stationary type exercise machines which have a frame with elongate pedal platforms located on either side of the frame which provide surfaces on which a person's feet are able to be placed. Opposing ends of the elongate pedal platforms are interconnected via a linkage mechanism with the frame such that the pedal platforms are moveable in a generally elliptical path. In use, the person moves the platforms in the elliptical path such that the person's feet remain generally in contact with the pedal platforms. This assists to alleviate impact injuries associated with the person's foot coming into contact with the surface.
A disadvantage of these elliptical trainers is that the elliptical path traced by the pedals is not sufficiently the same as or suitably approximate to the natural path of the feet traced by a person when jogging and/or running. In particular, the mechanical properties of the elliptical path causes a higher resistance level at the beginning of each weight-bearing stride than during the stride itself. This results in muscle recruitment and activation patterns that are different to running. A person using an elliptical trainer will tend to counteract this higher resistance at the beginning of the elliptical stride by leaning forward. This places more weight on the persons forefoot, engaging the quadriceps and hip flexor muscle groups, and altering the mechanics at the patella, or kneecap, which in turn can strain the knees and cause knee pain after prolonged use.
Furthermore, it is also known to provide a self-propelled exercise machine or apparatus such as bicycle, which includes an elliptical trainer type drive mechanism. More specifically, similarly to the elliptical trainer, the bicycle has a frame with a forward wheel, a rear wheel, and two elongate pedal platforms, which are interconnected with the frame via a linkage mechanism. Each of the elongate platforms is interconnected at opposing ends to the front of the frame and to the rear of the frame, respectively. The bike and the drive mechanism are arranged such that each of the platforms moves in a generally elliptical path so as to propel the bicycle.
As aforesaid, the elliptical motion of such pedal platforms is generally not sufficiently the same as or suitably approximate to the natural path traced by the feet of a person when running. Furthermore, the linkage mechanism to couple the pedal platforms to the frame is generally relatively bulky and is typically located in a position, such as at the rear of the bicycle, which is either awkward and/or potentially unsafe to a person using the bicycle. Moreover, the step-up height from the ground surface to the pedal platforms is uncomfortably high, making starting and stopping the bicycle and riding at low speeds, like for instance climbing a steep hill, awkward and/or potentially less safe to a person using the bicycle.
There is a need for a drive assembly, to drive a machine or apparatus such as a bicycle or a stationary exercise machine, a bicycle, a stationary exercise apparatus, a self propelled exercise machine or apparatus, and/or components thereof, which addresses or at least ameliorates one or more problems inherent in the prior art.